1. Field of the Invention
This invention relates to a dendron with hydrophobic functional of end group, a polyurethane with the dendron, and producing methods thereof, and more particularly, the end group of the dendron includes alkyl chains or perfluoroalkyl chains, such as C10˜C18 or perfluoroalkylethyl derivatives with more-than-four carbons.
2. Description of the Prior Art
In the recent years, there are more than 2000 relevant literatures about dendritic molecular chemistry. Dendrimer has a highly regular branched structure. By the step reaction, the molecular size thereof could be precisely controlled and it could be diversified. Buhleier et al. used addition and reduction reaction of acrylonitrile to produce dendrimer-like branched amines, i.e. hyperbranched polymer, in 1978. Tomalia et al. first published nano-dendritic poly(amidoamine) dendrimer in 1984 and also have established the record of earliest commercialization. The dendrimer consists of three basic structures including (1) core, (2) repeating unit, and (3) periphery group. The synthesis path could be classified by the growth direction into divergent type and convergent type.
In the prior art, for skipping the complicated steps of protection and dis-protection, improving productivity, and efficiently extending the generation growth, bifunctional build unit IDD (4-isocyanato-4′(3,3-dimethyl-2,4-dioxo-azetidino)diphenylmethane) is taken as the base. A series of regular dendrimers of derivatives of malonamide and urethane are developed by using the high reactivity of isocyanate and selective reactivity of azetidine-2,4-dione to perform alternating synthesis reaction with different alcohols and amines. The flow chart is shown in FIG. 1.
In addition, the side-chain dendrimer could be regarded as a structure copolymer of linear polymer and dendrimer. In the patent by Tomalia et al. in 1987, a dendrimer with a main chain of line polyethylenimine (PEI) is first mentioned. According to the literature, the side-chain dendrimer could be applied in the fields of self-assembly, nano leads of mono-molecule, light-emitting material, catalyst, and so on.